On the Suitability of Prehistoric Anthropogenic Burnt Sediments (Fumiers) for Archeomagnetic Studies at El Mirador Cave (Burgos, Spain)

Abstract

The analysis of the magnetic record of burnt archeological materials provides valuable information of both chronological and geophysical interest. Archeomagnetic studies carried out on independently well-dated materials allow to obtain data in order to improve and temporally extend the reference curves of the variations of the Earth’s magnetic field (EMF) at regional scale (the phenomenon called “secular variation”, SV). These curves, which mainly cover the last 2–3 millennia, can be used to carry out the archeomagnetic dating. Recent research on combustion episodes from mid-late Holocene European anthropogenic cave sequences (cf. fumiers) has revealed their suitability to obtain new directional data for temporal periods poorly covered in the reference SV curves or geomagnetic field models. El Mirador cave is an ideal site for this aim. Here we present the archeomagnetic study of 5 Holocene combustion episodes from El Mirador cave. Sampling technique is discussed and the new directional results along with a comprehensive study of their magnetic properties are assessed in connection with the previous published data. Furthermore, potential and limits of these materials to improve the archeomagnetic dating technique for the Late Prehistory are also discussed.